A protein having an insect resistance (hereinafter referred to as “insect-resistant protein”) is a material essential for transferring genes into a plant to carry out hereditary breeding of a genetically insect-resistant plant. It may be also used as a novel insect-resistant agent such as agricultural chemicals by spraying an insect-resistant protein expressed in microorganisms, cultured cells and individual multicellular animals and plants and recovered.
Insect-resistant proteins which are widely industrially used include Bt toxins (proteins) produced by Bacillus thuringiensis, which is a Gram-positive bacterium.
Such Bt toxins at low concentrations (about 1 ppm) are known to exhibit insecticidal and insect-resistant activities (e.g., see Non-Patent Document 1 or 2).
However, the above Bt toxins are derived from bacteria and thus have a deep-seated resistance for use as genetic resources for recombinants, such as gene recombination, and therefore it has been desired to detect insect-resistant proteins derived from plants.
In contrast, as insect-resistant proteins derived from plants, protease inhibitors derived from Vigna sinensis (for example, see Non-Patent Document 3 or Patent Document 1), amylase inhibitors derived from kidney beans (for example, see Non-Patent Document 4) and lectins derived from snowdrop (for example, see Non-Patent Document 5 or Patent Document 2) have been known.    Non-Patent Document 1: Canadian Journal of Microbiology 51, 988-995 (2005)    Non-Patent Document 2: Journal of Pesticide Reform 14, 13-20 (1994)    Non-Patent Document 3: Pest Management Science 57, 57-65 (2001)    Non-Patent Document 4: Plant Physiology 107, 1233-1239 (1995)    Non-Patent Document 5: Journal of Insect Physiology 43, 727-739 (1997)    Patent Document 1: U.S. Pat. No. 4,640,836    Patent Document 2: U.S. Pat. No. 5,545,820